PV1
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Re: Off-Grid Solar Install

Sat Dec 17, 2016 5:13 pm

Tesla makes the Smart car battery modules, but they are different than Model S modules (and more expensive per kWh). The Smart modules run higher voltage, but have fewer cells. I don't see the Model S modules on EVWest.com.

Apparently, there are a lot of Smart EDs being parted out, given the parts that EVWest has.

They look like fun guys to hang out with, though.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

PV1
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Re: Off-Grid Solar Install

Mon Dec 19, 2016 6:16 pm

Battery modules have shipped. Should see those early next week. FedEx Ground right to the house 8-) .

The inverter and charge controller are being shipped by pallet due to weight, so that will be dropped at my work, and I'll break the pallet down and load everything into the i-MiEV (ought to handle 100 lbs. of equipment, right? :lol: ).

The solar panels will arrive at my friend's place on a pallet, but those will be picked up in the truck, likely on Saturday if they arrive in time.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

pbui19
Posts: 137
Joined: Tue Jan 07, 2014 12:17 pm

Re: Off-Grid Solar Install

Wed Dec 21, 2016 8:33 am

PV1- looks like a fun project. I briefly scanned the Midnight 150 charge controller, it doesn't seem to have lithium charge profile. Am I missing something ? the Outback inverter has lithium charging option. Does the Tesla pack already have built-in BMS ? may be the 150 can be programmed to stop below 40vdc ? then you can top off with the Outback.

PV1
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Re: Off-Grid Solar Install

Wed Dec 21, 2016 10:46 am

The Classic has a custom setting that I can use and set the charged voltage manually. I plan to only charge the bank to 49.2 volts (4.1 volts per cell). I'll also be disabling the equalizing function and temperature compensation (which shouldn't be an issue anyway, as my basement holds a pretty stable 65 F) to prevent over-charging. I can safely go to 50.4 volts, but operating voltage range of the pack is 42-49.2 volts (3.5-4.1 V/cell).

The modules each have a BMS board on them that appear to function on their own. I have a lithium balance charger that I'll use to make sure all the modules are balanced and at the same charge level. Given that they came out of relatively new packs, they should already be balanced (especially if they're all from the same pack). I may end up using the "Garcia Bros. BMS" :lol: , given my voltage range and relatively low current draw.

The Outback's charger uses grid power to charge the battery bank. That's not the goal of this system. Ideally, this system is off-grid, but if it does end up needing a grid connection to be reliable, then I'll need to figure out which method allows for the following:

1. Runs independently on battery/solar power.
2. Automatically connects to grid to support loads when batteries deplete. Automatically disconnects when batteries are charged.
3. Grid does not charge the batteries.
4. Automatically connects to grid to sell excess solar power when batteries are full. Automatically disconnects when excess is no longer available.


As a bonus feature, I'd like to give the system control of interior lighting circuits for dusk to dawn operation for the pair of lamps that we leave on all night.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

JoeS
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Re: Off-Grid Solar Install

Wed Dec 21, 2016 3:59 pm

PV1, you're going with a fancier system than me, undoubtedly better in the long run. Your voltage levels are right on for 12 Li(NMC?) series cells. In my case, I have three parallel strings of 4S 12v AGMs, 16S LiFEPO4, and 14S Li(NMC), each string of similar capacity, intending for them all to play nicely off a single charger at a max charging voltage of around 56v. Need to finish instrumenting this setup to see how well they share both charging and discharging currents before proceeding further - exactly where I was a year ago before being rudely interrupted :evil: .
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

PV1
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Re: Off-Grid Solar Install

Thu Dec 22, 2016 12:43 pm

I believe they're lithium cobalt oxide, but I'm not certain. Each module is 6s74p, and the battery will be wired two parallel strings of two modules in series, for a combined 12s148p cell configuration. At full output, each string has just over 50 amps draw, making for less than 1 amp per cell.

While I'm actually less than 48 volts "nominal", the inverter shuts down at 40 volts input, or 3.33 volts/cell, keeping the batteries from getting near a critical level. I should be able to program the inverter to shutdown at 42 volts, leaving that bit at the bottom for when I really need it, and to not stress the cells more than necessary.

I could've went for a cheaper off-grid only inverter, but knowing that someone else used the same components and everything worked together, I felt the few extra bucks was worth the peace of mind.

Batteries were delivered to the house this morning :mrgreen: ! Right now, they are in the back of Koorz. If they were hooked up, total range would be 140 miles while only adding an additional 220 lbs. :lol: .
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

PV1
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Re: Off-Grid Solar Install

Thu Dec 22, 2016 3:35 pm

https://www.dropbox.com/sh/tmj7298pl9q9 ... Y7Qba?dl=0

Garcia Bros. BMS it is :x . The modules don't have the BMS board on them. But here are pictures.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

PV1
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Posts: 2864
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Location: Pittsburgh, PA
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Re: Off-Grid Solar Install

Thu Dec 22, 2016 6:27 pm

Also, according to my charger, 3.33 volts per cell is just over 5% charge. That's the lowest the inverter will go before shutting down. I'll see sometime later what 3.5 volts per cell is considered, as that will likely be my "dead battery" point.

Right now, I'm trying to bring the first module up to about 10% charge. One bank of cells are just a hair higher than the others (.02 volts).

I just got word that the solar panels have arrived at my friend's place. I'll be picking those up Saturday.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

PV1
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Posts: 2864
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA
Contact: Website

Re: Off-Grid Solar Install

Fri Dec 23, 2016 7:42 am

I put 1.5 Ah into the module in about an hour, hardly moving the voltage, but I ran out of time last night. If I were to fully charge a module, it would take my lithium charger over 100 hours at full bore. It's only a 50 watt charger :lol: . Even running at 40 watts, it was getting warm.

I also emailed the seller. She said they recently started removing the BMS boards when they add their balancing connector as the boards don't appear to work outside of the car, but offered to send them to me if I wanted them, which I do.

Just as I about hit Submit on this, a box showed up containing the MATE3 control panel, combiner box, PV breakers, and charge controller. I wasn't expecting these until next week (thought they would've been with the inverter, which will be delivered on the 27th).

It's satisfying to finally have the Classic in my possession. When I was dreaming about building a solar car (before the i-MiEV), I followed the Classic's development with anticipation.

Can't wait to get everything hooked up and tested. :D
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

pbui19
Posts: 137
Joined: Tue Jan 07, 2014 12:17 pm

Re: Off-Grid Solar Install

Sat Dec 24, 2016 9:30 am

how about posting a block diagram so we can follow your train of thought ?

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